The present proposed research is based on a major breakthrough that I have made in surgical ovariectomy in ring doves. Technical difficulty of ovariectomy in avian species has been one of the stumbling-blocks in research on female avian species, resulting in a major lag of research data on avian hormone-behavior relationships. I have, in my previous work, developed a scale of normative behavior repertoire in female ring doves, and established the relationship between ovarian hormones and the behavior, by the method of ovariectomy followed by exogenous estrogen or progesterone replacement therapy. One of the objectives of this research is to explore the central mechanisms by which ovarian hormones influence female behavior and morphological changes that culminate in egg-laying. The method involves local brain hormones implant, and biochemical study of the hormones concentration in the brain. The second objective is to analyze the role and the nature of the hypothalamohypophyseal complex in mediating gonadal activity and the expression of the gonadal function in male and female doves. The method involves (1) measurement of plasma LH (FSH) level during the breeding cycles, (2) effect of hypophysectomy on the effectiveness of gonadal hormone treatment, and (3) influence of photo-stimulation on the nature and the rate of loss of gonadal function as well as the sensitivity in response to hormone treatment. I should emphasize that these proposals are planned to provide compositive information on one species (ring doves) for theoretical considerations of hormone and behavior with respect to species-specific behavior patterns. Equally important is that ring dove research reveals aspects of hormones-behavior relationship that have not been explored in mammalian species thus contributing to these areas of research in general.